ABSTRACT The aim of study was to determine the relationship between metabolic parameters, body weight and body growth of piglets at birth and weaning. The experiment included 80 piglets obtained from F1 generation sows. Body weight was measured at birth (BW0), 24h (BW1) after birth and on day 25 (at weaning, BW2). Blood sampling was performed at the beginning of life (3rd day after birth) and at weaning (21st day after birth). BW0 and BW1 positively correlated with cholesterol and negatively with urea values at the beginning of life and RBC values at weaning. BW2 positively correlates with albumin and cortisol values at the beginning of life, total proteins, and globulins at weaning, and negatively correlates with erythrocyte values at weaning. Piglet growth from birth to weaning (BWG2-0) correlates positively with total proteins, albumin, and cortisol at the beginning of life and total proteins at weaning. ROC analysis shows that MCHC, TPROT, GLOB, CHOL and AST at the beginning of life can distinguish fast-growing from slow-growing piglets from birth to weaning period. The use of blood parameters enables early recognition of growth rate in piglets, which can help to optimize all further steps to achieve the best possible growth.